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Academic Commons Search Resultsen-usHeat Transfer Model of Hyporthermic Intracarotid Infusion of Cold Saline for Stroke Therapyhttp://academiccommons.columbia.edu/catalog/ac:128323
Neimark, Matthew A.; Konstas, Angelos-Aristeidis; Laine, Andrew F.; Pile-Spellman, Johnhttp://hdl.handle.net/10022/AC:P:9456Thu, 12 Aug 2010 00:00:00 +0000A 3-dimensional hemispheric computational brain model is developed to simulate infusion of cold saline in the carotid arteries in terms of brain cooling for stroke therapy. The model is based on the Pennes bioheat equation, with four tissue layers: white matter, gray matter, skull, and scalp. The stroke lesion is simulated by reducing blood flow to a selected volume of the brain by a factor of one-third, and brain metabolism by 50%. A stroke penumbra was also generated surrounding the core lesion (blood volume reduction 25%, metabolism reduction 20%). The finite difference method was employed to solve the system of partial differential equations. This model demonstrated a reduction in brain temperature, at the stroke lesion, to 32°C in less than 10 minutes.Biomedical engineeringal418, jp59Radiology, Biomedical EngineeringArticlesLocal Control of Temperature in a Theoretical Human Model of Selective Brain Coolinghttp://academiccommons.columbia.edu/catalog/ac:128314
Neimark, Matthew A.; Konstas, Angelos-Aristeidis; Choi, Jae H.; Laine, Andrew F.; Pile-Spellman, Johnhttp://hdl.handle.net/10022/AC:P:9453Thu, 12 Aug 2010 00:00:00 +0000A method of feedback control of local brain temperature during therapeutic intracarotid cold saline infusion is presented and tested on a theoretical cerebral heat transfer model based on the Pennes bioheat equation. In this temperature control method, the infusion rate of cold saline is varied based on the rate of temperature change, and the deviation of temperature to a target, within a voxel in the treated region of brain. This control method is tested in cases where the head is exposed to ambient room temperature, and where the head is packed in ice. In both the ice and non-ice cases, target temperature (33degC) is achieved in the voxel according to the desired time constant (2 minutes). Two hours of treatment decreased the required inflow of ice-cold saline from 30 ml/min to 21 and 7 ml/min in the non-ice and ice cases, respectively. Intracarotid hematocrit had higher values in the non-ice case.Biomedical engineeringal418, jp59Radiology, Biomedical EngineeringArticlesThe Role of Intracarotid Cold Saline Infusion on a Theoretical Brain Model Incorporating the Circle of Willis and Cerebral Venous Returnhttp://academiccommons.columbia.edu/catalog/ac:128317
Neimark, Matthew A.; Konstas, Angelos-Aristeidis; Choi, Jae H.; Laine, Andrew F.; Pile-Spellman, Johnhttp://hdl.handle.net/10022/AC:P:9454Thu, 12 Aug 2010 00:00:00 +0000This study describes a theoretical model of brain cooling by intracarotid cold saline infusion which takes into account redistribution of cold perfusate through the circle of Willis (CoW) and cold venous return (VR) from the head. This model is developed in spherical coordinates on a four tissue layer hemispherical geometrical configuration. Temperature evolution is modeled according to the Pennes bioheat transfer equation. Simulations were run over a 1 hour period and 30 ml/min of freezing cold saline with the baseline model (no VR, no CoW), VR model (without CoW), and CoW model (with VR). The VR model demonstrates continuing temperature drop in the treatment region of the brain not observed in the baseline model and its final mean ipsilateral anterior temperature was approximately 31 degC. The temperature effect in the CoW model was present but less robust in the ipsilateral anterior region, as final temperature was 32 degC. However, cooling was also achieved in contralateral and posterior brain regions. This model continues to demonstrate the feasibility of intracarotid cold saline infusion for ischemic stroke therapy.Biomedical engineeringal418, jp59Radiology, Biomedical EngineeringArticles